VOX is USELESS to fix an 8 month mail problem

ACC: 128260 I had a lantic address since 2002. Then a few years ago it was changed to VOX. Since June last year, 2020 I have a problem with sending mail with VOX. Receiving is OK. I have spoken to their technical people every week, at least 40 times. Often 40 minutes at a time. They have been in my computer twice to check my settings. They say my IP address is blocked. I only send about 6 mails a week but they are business and important. They do something to unblock it and it works for a day. Last week I was asked to install Makwarebytes to check my computer. Computer is fine. The message I get Is "Outgoing server (SMTP) smtp.voxtelecom.co.za timed out." My Google mails work fine. I would like to keep this address as it is a big mission to change address with all contacts. I have had Vox fibre 50/5 for 3 years and am looking around to get away from VOX. If this is not fixed in TWO weeks I'll be going FB and anywhere else I can. PLEASE JUST FIX THIS IP ADDRESS.